Underreamer



Feb. 9, 1932. J. GRANT ET AL. 1,844,358

UNDERREAMER Filed March 18, 1930 3 Sheets-Sheet 1 I72 menial-a Jbfin Gravy? James 7.5mm? aye.

- Feb. 9, 1932. J. GRANT ET AL 1,844,358

UNDERREAMER Filed March 18, 1930 3 Sheets-Sheet 2 lI/l I T 7 [a E k 7 2/1,, 1 V,

E a/ J/ I I Feb 1932- J. GRANT ET AL UNDERREAMER Filed March 18, 1930 3 Sheets-Sheet C5 Qfa In 0 6)? [*0/13 70/722 'ragzt. James. .2 fian/z 90.

Patented Feb. 9, 1932 UNITED STATES PATNT @FFICE JOHN GRANT AND JAMES J. SANTIAGO, OF LOS ANGELES, CALIFORNIA; SAID SANTIAGO ASSIGNOR T0 SAID GRANT UNDERBEAMER Application filed March 18, 1920. Serial No. 436,713.

This invention has to do with expansive rcamers or underreamers of the general type involving a cutter-carrying body and an internal abutment upon which the cutters move for expansion and for support in expanded position. Typical examples of the general type are shown in the Brown Patent No. 1,454,843, dated May 15, 1923; Phipps Patent No. 1,678,073, dated July 241, 1928, and in ap- Jlication Serial No. 254,266, filed February 1 1, 1928, filed by John Grant, one of us.

In an expansive reamer of the general type referred to, it may be stated as one of the objects of this invention to provide an internal cutter abutment upon the body itself, or to provide such an abutment upon the body in addition to an abutment upon an expansion mandrel or core. It is also an object of our invention to provide a structure in which the internal mandrel or core does not necessarily extend longitudinally throughout the length extent of the cutters, or in which the abutment mandrel, as a separate piece, may virtually he eliminated entirely; and to provide, in such a structure, a cutter formation and arrangement such that a virtually fluid-tight water-course is maintained through the space between the cutters, although no passage tube is used.

There are other objects and (OII'QSPOHCling features of the invention; but all these, and the invention itself, will be better understood from a consideration of the following detailed and specilic descriptions of preferred and typical designs which form illustrative embmliments of the invention. For the purpose of such description we refer to the accompanying drawings, in which;

Figure 1 is a central longitudinal section of one form of expansive reamer showing the parts in expanded positions;

Fig. 2 a. similar view showing the parts in contracted position;

Fig. is a fragmentary detail of the body, in longitudinal section;

Figs. 3, 4 and 5 are, respectively, enlarged cross sections on lines 3-3, i-a and 55 of Figure 1;

Figs. 6 and 7 are, respectively, enlarged cross sections on lines 66 and 7-7 of Figure 2;

Fig. 8 is a side elevation of a cutter such as shown in the preceding figures;

Fig. 9 is a front elevation of the same;

Fig. 10 is a central longitudinal section of another form of expansive reamer showing the parts in expanded position;

Fig. 11 is a similar View showing the parts contracted;

Figs. 12, 13 and 14, are respectively en larged cross-sections on lines 12--12, 13-13 and 14;--1 r of Figure 10;

Fig. 15 is a side elevation of a cutter carrier such as shown in Figures 10 and 11, and

Fig. 16 is a front elevation of the same.

In the drawings, and referring first to the form shown in Figures 1 and following, we show a body 10 which is more or less tubular in form, having an internal bore 11 extending up from its bottoniend and terminating at a downwardly facing shoulder 12 in the upper part of the body. The termination of this bore 11 at the shoulder 12 may be most clearly seen in Figure 2a. Extending through the tubular body wall a plurality of wall slots 13, here illustrated as three in number because the cutters are chosen to be three in number. These body slots 13 are slots which pierce the tubular body wall up to the level of shoulder 12; above that shoulder the slots 13, or what niiight he called their upper extensions, have back walls 141, which are here shown as slightly inclined to the longitudinal axis and also are here shown as surfaces of the integral body 10. The cross sectional conformation of the body, and the arrangement of the upper parts of slots 13 in the body, is best shown in Figure 3.

The upper part of body 10, above the upper end of bore 11 has a central circulation passage 15; and this passage continues as a bore 16 through the tubular member 17 which is set in an enlargement 18 of bore 1 1 and has its lower end projecting below shoulder 12 andinto the main body bore 11. Member 17 has an ani'iular flange that bears upwardly against shoulder 12 and presents a downwardly facing diagonal. or conical surface 19 which slopes upwardly and outwardly away from the central axis of the body. Below this annular flange the member 17 has a short downward and preferably cylindric extension 20 which forms the internal support or stop for the upper ends of the cutters when they are contracted, as shown in F igures 2 and 6; limiting the inward movements of the upper ends of the cutters to such positions as shown in those figaires.

Members 17 may, if desired, bemadeintegrally with the body; it is preferably made as a separate piece in order that the conical or diagonal surface 19, which'is the cutter expanding surface, may be composed of a metal better suited to resist wear than is the metal best chosen for the whole body.

The cutters, as here illustrated, are composed of cutter carriers 25 and cutter rollers 26, the rollers being mounted on spindles 27 which are mounted in the carriers. The cutter structure here illustrated is typical; but insofar as the present isconcerned it is immaterial what the particular cutter structure may be. life therefore refer to the carrier and roller combination simply as a cutter.

. These cutters lie in body slots 13 and have laterally extendingwings or ribs 30 at their back sides, which wings internally overhang the lateral edges of slots 13 to limit the outward movement of the cutters through the body slots. Wings 30 are so inclined to the lengths of the cutters as to bear outwardly against the internal body surface when the cutters are in their inclined expanded positions such as shown in Figure 1; and the upper ends of the wings terminate at 31 (see particularly Figures 8 and 9), so that the upper ends .of the wings abut upwardly against body shoulder 12 when the cutters are in their uppermost expanded positions of Figure 1. Thus, in their uppermost and expanded positions, the-wings bear outwardly against the internal body wall from the shoulder 12 downwardly to the lower ends of the cutters.

The cutters rest at their lower ends on a propeller plunger 33 which moves upwardly by the application of suitable force. The rcamers here illustrated are spring-actuated, and thus the cutter actuating spring 34 is enclosed within the lower part of body bore 11 and presses upwardly on the propeller 33 with considerable force. The lower end of the spring may be supported in any suitable manner, being here shown as supported by the tool joint pin 35 of'drill bit 36, the pin 35 being screwed into a tubular adapter or stub 37 which may be regarded as a part of the body. It is convenient and advantageous to make the adapter 37 a separate piece because thereby its spring receiving bore 38 may be made smaller than the body bore 11, and may thus fit the lower part of the spring 34 rather snugly to guide the spring.

A central circulation bore 40 extends through propeller 33 to deliver circulating fluid downwardly through the propeller into the spring bore, whence the circulating fluid is directed to circulation passage 41 of the drill bit and also is directed upwardly and outwardly through inclined grooves 0r notches 42 underthe'cutters. These grooves 42 are formed in the inner wall of the tubular body just below the lower ends of Wall slots 13. Their position issuch that theyare covered by propeller 33 when the propeller is down and the cutters contracted, but are uncovered when the propeller is in its upper position of Figure 1..

By reference to the section of Figure 3 it will be noted the back walls 1'4of the upper parts-of slots 13 are preferably flat. The back surface 45 of the upper part of each cutter is likewise plane so as. to hear back flatly against back surface 14 when the cutters are this expanded position; the cutter wings 30 bear outwardly against the body wall leave an open passage centrally through the cutterassemblage, asis clearly shown in the figures referred to. The circulating flu d,

in the expanded position of Figure 1. In

forced down through the body passage 15 passes into the-bodybore 11 in the space between the assemblage of cutters, and thence passes on down through propeller bore 40 into the body bore below. Between the body shoulder 12 and propeller thereis, in the construction here shown.,no internal mandrel or. other tubular member forming a circulation passage. The passage throughout the vertical length referred to, is virtually formed and enclosed by the cutter assemblage .and the body. The cutters fit" the body slots 13 fairly snugly and, as before stated, the cutter wings bear outwardly against the internal body surface from the propeller 33 upwardly to the bore terminating shoulder 12. WVith the. wings so bearing outwardlyagainst the body wall at the sides of the slots, any fluid leakage through the slots around the cutters is virtually sealed, or at least is minimized. The propeller plunger 33 closes the lower ends of body slots13 below the lower ends of the cutters.

In their lowermost and contracted positions the upper inner corners of the cutters ill:

per ends of the cutters when they are moved upwardly by spring; action, throwing; the cutter faces outwardly to position where they then ride upwardly on body surfaces 141;, the cutters linally reaching the uppermost ex panded positions shown in Figure 1. Having reached such positions, where they are stopped by the upper ends of the cutteis bringing up against upper end walls -fl-7 of the body slots, or by the upper ends of wi s bl) bringing up against limdy shoulder l the cutters then at their upper ends bear i. hardly against body suriliaces it only, having no inward bearing against the expanding member 17 or against the enpandin ur'liace ll). And at their lower ends the cutters bear inunrrdly against each other, and bear outwardly against the body wall througlmut their lower extent from body shoulder 12 downwardly.

In Figure 10 and following we show a somewhat dillerent structure. Here the cutters have, in their upper parts, a baclt nearing; against a n'iandrel surface Lilo, formed on an internal cutter expanding; and abutment inand rel 17a which is ,rew-threadedly connect-- ed with body 10a and extends down into the body somewhat below the upper ends of the cutter-rcceiving slots 13a. This mandrel, in its part which extends below the upper ends of the body slots. is smaller in diameter than the body bore 110, leaving an annular $2 510; between the tapered mandrel surface 14c and the body wall, so that the cutter wine's She may in this form extend virtually to the upper end of the cutters. These cutter wings, e1:- cepting that they extend to the upper ends oil the cutters, are tormcd substantially as here iuluztorc described. and bear inwardly agairr-t each other at their lowermost ends when the cutters are eI-LpaMled, as is shown in Figure I l. The cutter abutment surface .l la being, in this form, circular the rear bearing tacos loci are correspondingly curved. See Figure 13.

At the upper ends oi the body slots 13a, which extend through the tubular body wall, these slots have extensions 13?). The slot cxtensions 136 have back walls in) in the body. Upward extensions 25a of the cutter carriers 25 enter these slot extensions when the cutters a re uppermost; and the back bearing surfaces l5?) of these extensions hear back against the bearing surfaces 14?).

Other than specifically described, the structure shown in Figures 10 and 11 is substantially the same as that shown in the first figures. The cutter propeller 33 is the same and is operated by spring in the same manner. The spring bore 38c may here, however, be formed directly in the body proper, the main and larger bore 11c here being open at the. upper end of the body for insertion of the parts. The internal abutmentmandrel 17o carries the diagonal cutter expanding surface or surfaces 19c at its lower end, and has a downward extension 20w which forms the internal limiting}; stop for the inward movement at the upper ends of the contract ed cutters.

The lower back surfaces of the cutters are recessed as is best shown at dGa in Figure 14, to form the passage for circulating fluid as before described. The cutters in Figure 10 and following; being shown as two in num her, the specific formations of the back parts oi the cutters are different from those shown in Figures 1 and following; but the formations are similar, as is readily apparent upon inspection of the drawings.

The structure herein described is closely related in several features to that shown and claimed in the copending application, Scr. No. 254,266, filed February 14th, 1928. For instance, that application also shows cutters which bear against each other at their lower ends and thus need not depend on the internal mandrel for support at that point. The distinc'tion in this present application is in the fact that the upper cutter ends have internal hearings on the integral body itself either in addition to their bearings inwardly on the separate piece mandrel, or to the entire elimination of the mandrel; and also that the lower ends of the cutters have .no bearing at all on internal mandrel but only on themselves.

We claim:

1. lin an expansive reamer, a vertically extending cutter carrying body, a plurality of Vertically extending cutters mounted in the body and vertically movable therein, cutter actuating means tending to move the cutters upwardly, the body having integral outwardly facing cutter abutment surfaces onto which the upper ends of the cutters ride when they move upwardly, and the lower ends of the cutters being' so formed that they bear inwardly mutually against each other.

E2. In an expansive reamer, a vertically extending: cutter carrying body, a plurality of vertically extending cutters mounted in the body and vertically movable therein, cutter actuating; means tending to move the cutters upwardly, the body ln-Wing integral outwardly facing; cutter abutmentsurtaces onto which the lll 'lptll ends of the cutters ride when they move upwardly, the lower ends of the cutters being so formed that they bear inwardly mutually against each other, and the cutters having outward bearing); against the body.

3, In an expansive reamer. a vertically extending tubular cutter carrying body ha ing: vertically extending cutter carrying; slots through its tubular wall, vertically i'novable cutters mounted in the body slots, cutter actuatinp; means teinlinef to move the cutters upwardly; said body slots having extensions at their upper ends and which extensions have back surfaces integral in the body, the upper ends ol the cutters having back surfaces I which ride out onto the back surfaces of the said slot extensions when the cutters are moved upwardly, the lower endsof the cutters being formed so that they bear in wardly against each other.

4:; In an expansive reamer, a vertically extendingtubular cutter carrying body having vertically extending cutter carrying slots through its tubular wall, vertically movable cutters mounted in the body slots, cutter actuating means tending to move the cutters upwardly; said body slots having extensions at their upper ends and which extensions have back surfaces integral in the body, the upper ends of the cutters having back surfaces which ride out'onto the back surfaces of the said slot extensions when the cutters are moved upwardly, said cutters having laterally proiecting wings at their inner edges, which wings extend from the lower ends of the cutters up to the level of the upper end oflthe body slots, said wings at the lower ends of the several cutters being formed to bear inwardly against each: other. 5. In an expansive reamer, a vertically extending body having a'vertically extending bore leading up from its lower end and ter- Ininating within the body'at a. downwardly facing shoulder, vertically extending cutter receiving slots through the body wall below said shoulder, said slots having upward extensions in the body above said shoulder and said upward extensions having back walls integral in the body, vertically extending outters in the slots, cutter actuating means tending to move the cutters upwardly, the upper ends ofthe cutters riding upwardly into'thc slot extensions and bearing inwardly against said back walls, and laterally extending wings on the cutters which bear outwardly against the body wall from the body shoulder downward, the lower ends of the cutters and wings being formed to bear inwardly against each other.

6. In an expansive reamer, a vertically extending body having a vertically extending bore leading up from its lower end and terminating within the body at a downwardly facing shoulder, vertically extending cutter receiving slots through the body wall below said shoulder, said slots having upward extensions in the body above said shoulder and said upward extensions having back walls integral in the body, vertically extending cuttersin the slots, cutter actuating means tending to move the cutters upwardly, the upper ends of the cutters riding upwardly into the slot extensions and bearing inwardly against said back walls, and laterally extending wings on the cutters which bear outwardly against the body wall from the body shoulder downward, the lower ends of the cutters and wings being formed to bear inwardly against each other; the body bore being open and unobstructed except for the cutters and cutother ends of the cutters beingso formed that they bear inwardly mutually exclusively against each other. I

In witness that We claim the foregoing we have hereunto subscribed our names this 25 day of February 1930.

' JOHN GRANT.

JAMES J. SANTIAGO 

